Intra-oral tracer having a scriber for indicating vertical position of dentures



Aug. 8, 1961 c. B. MCLEOD 2,994,957

INTRA-ORAL TRACER HAVING A SCRIBER FOR INDICATING VERTICAL POSITION OFDENTURES Filed Sept. 13. 1956 5 INVENTOR.

CA HIP/0N 5. NH E00 INTRA-ORAL TRACER HAVING A SCRIBER FOR INDICATINGVERTICAL POSITION OF DENTURES Clarion B. McLeod, Cleveland, Ohio,assignor to Smith and McLeod Dental Laboratories, Cleveland, Ohio, apartnership of Ohio Filed Sept. 13, 1956, Ser. No. 609,597 11 Claims.(Cl. 32-19) This invention relates to improvements in the manufacture ofdental plates and more particularly to what is known as an intra-oraltracer. The purpose of this tracer is to assist the dentist andlaboratory technician in so shaping and forming the plates as to insureproper vertical spacing between the jaws and thus not only secure acorrect bite but also preserve or produce the most desirable contour ofthe lips, cheeks and other soft tissues.

One of the objects of the present invention is to provide a device fordetermining graphically the working bite of the human patient with theworking bite determining the space between the jaws.

A further object of the present invention is to provide an intra-oraltracer for determining the working bite and gothic arch by the normalmovement of the mandible or lower jaw.

A further object of the present invention is to provide a method ofdetermining the working bite position of the jaws of a human patient byinducing the patient to swallow and then recording the closest approachbetween said jaws during swallowing.

A further object of the present invention is to provide a simpleapparatus for recording graphically the working bite obtained by themethod set forth in the previous paragraph.

A further object of the present invention is to provide an intra-oraltracer for determining the working bite and gothic arch respectively byinducing the patient to swallow and to move his jaws from side to sideto generate a gothic arch wherein said tracer has at least one of theelements of the gothic arch generating components removably securedtherein to permit removal from the mouth during determination of theworking bite so that said element does not interfere with the normalswallowing by the patient.

A further object of the present invention is to provide an intra-oraltracer characterized by its structural simplicity, ease of assembly ofits parts, and simplicity of operation or usage.

Other features of this invention reside in the arrangement and design ofthe parts for carrying out their appropriate functions.

Other objects and advantages of this invention will be apparent from theaccompanying drawings and description and the essential features will beset forth in the appended claims.

In the drawings,

FIG. 1 is a side elevational view of the face of a human patient withthe intra-oral tracer mounted therein and shown in vertical sagittalsection through the median plane of the human masticatory mechanism withthis view including both the upper and lower members carried by therespective jaws, a verti-scriber unit for determining the working biteand a verti-tracer unit for generating the gothic arch;

FIG. 2. is a front view of the members and the vertiscriber removed fromthe mouth of the patient and having the working bite recorded thereon;

FIG. 3 is a bottom view taken in the occlusal plane along line 33 ofFIG. 1 of the upper member having the tracer of the verti-scriber unitand the markable sur face element of the verti-tracer unit;

Patented Aug. 8, 1961 ice FIG. 4 is a top plan view taken along line 4-4of FIG. 1 of the lower member having the markable surface of theverti-scriber unit, and having the tracer element and the operatingwrench therefor of the verti-tracer unit;

FIG. 5 is a longitudinal sectional view through the tracer element ofthe verti-tracer unit;

FIG. 6 is a top plan view of a portion of the connecting means betweenthe tracer element of the verti-tracer unit and the lower member;

FIG. 7 is an enlarged sectional view of the left-hand portion of FIG. 1disclosing a modified form of biasing construction for the tracer of theverti-scriber unit; while FIG. 8 is an enlarged view of theverti-scriber tracer with its sections flattened into coplanarrelationship.

Before the intra-oral tracer here illustrated and the method heredisclosed are specifically described in detail, it is to be understoodthat the invention here involved is not limited to the structuraldetails, arrangement of parts, etc. here set forth in detail sincemechanisms and methods embodying the present invention may take variousforms. It also is to be understood that the phraseology or terminologyherein employed is for purposes of description and not of limitationsince the scope of the present invention is denoted by the appendedclaims.

The intra-oral tracer and the method forming the subject metter of thepresent invention can best be explained by a description of thetechnique of which they form a part. It may be assumed, as an example,that a dental technician in his laboratory, possibly remote from theoffice of the dentist, is assisting in the preparation and fabricationof dental plates in accordance with measurements and other instructionsobtained and supplied to him by the dentist as a result of hisexamination of the patients mouth. The cooperative procedure of thedentist and his technician is as follows:

First, the dentist prepares a pair of upper and lower jaw impressions inplaster or any other suitable material by standard procedure requiringneither illustration nor detailed description.

Second, he prepares the usual mush or biscuit wax plate form (not shown)to simulate the true bite relation of the two jaws and to establish anarbitrary vertical spacing relation between them.

Now the two impressions and the mush or biscuit bite form are sent tothe technician who proceeds as follows:

First, he fabricates two models (not shown) from the two impressions,one for each jaw. The models are complementary to the upper and lowerjaw impressions furnished by the dentist and simulate the upper jaw andpalate and the lower jaw respectively of the patient. These models aremounted on the hinged arms of the usual articulator (not shown) by meansof which they may be relatively moved to simulate ordinary bite action.Base plate members are then made to conform with the models. The upperbase plate member 10 comprises an impression, similar to the impressionmade by the dentist, and includes an integral central portion 10a acrossthe palate. The lower base plate member 11 comprises an impressionadapted to fit the lower jaw of the patient. These base plate membersmay be made of any suitable material for the purpose, such as hardeningplaster or a synthetic plastic material. Each is a thin-walled,concave-convex member accurately conformed to fit the corresponding jawmodel member on its concave base and curved smoothly on its convex base.The technician attaches the two models to the articulator and adjuststhe articulator arm to close the base members 1% and 11 mounted thereontogether upon the mush bite form to thus bring them into exactly thesame bite relationship existing when the mush bite form was produced.Then, the closing stop on the articulator is set to establish thisrelation, which, of course, is the arbitrary vertical jaw spacing beforereferred to.

Then, the technician applies wax, such as at b and 11b, to thestabilized base plate members 10' and 11 to build them up to formrespectively bite block members 12 and 13. These members 12 and 13 areattached to the upper and lower jaws of the patient in the manner shownin FIG. 1.

At the same time, the technician imbeds in or secures to these members12 and 13 means operatively connecting the members for recording theworking bite distance between the jaws in response to swallowing by thepatient, with this means hereinafter called verti-scriber unit 15, andmeans operatively connecting these members for recording as a gothicarch the loci of the relative movement between the jaws in the occlusalplane during grinding of the teeth while maintaining the working bitedistance between the jaws, this means being hereinafter calledverti-tracer unit 16.

Verti-scriber unit 15 includes a plate with a markable surface thereoncarried by member 13 and a tracer 21 carried by member 12. Plate 20 hasan external surface, remote from member 13, capable of being marked uponand extending generally normal to the occlusal plane, which planeextends generally horizontally along the section line 33 or 44 of HQ 1.Plate 20 is inset into a recess in the lower bite rim of member 13 andis luted in place. Tracer 21 comprises two sections 2-2 and 23 pivotallysecured together by a hinge 24 having its pivot axis extending generallyparallel to the occlusal plane. The enlarged view in FIG. 8 of theflattened tracer 21 reveals that hinge 24 permits pivotal movement aboutthe axis of hinge pin 24a but prevents axial relative movement along theaxis between sections 22 and 23 because the pair of arms on section 22straddles the pair of arms on section 23.

Means is provided for detachably securing one section 22 to member 12and takes the form of a sleeve 25, C- shape in cross section, secured inmember 12 within which section 22 is telescopically and frictionallydetachably secured. The other section 23 is located between members 12,13 and the lips of the patient in about the same position as the teethwill be set so as not to interfere with the patients lips. Marking orstylus point 23a, on the distal end of section or stylus arm 23, bearsagainst the markable surface on plate 20 for recording the working biteposition, as will be brought out in more detail hereinafter.

Means is provided for biasing marking point 23a into marking contactwith the surface of plate 2b. This biasing means may take any one ofseveral forms. In FIGS. 1, 2, 3 and 8, a spring 26 is fixed respectivelyat its opposite ends to sections 22 and 23 with the helix thereofwrapped around the pivot pin 24a of hinge 24 between the arms ofsections 22 and 23 so as to bias section 23 in a counterclockwisedirection in FIG. 1 to urge point 23a against the surface of plate 20.in a second embodiment (not shown), an elastic band may be securedrespectively at opposite ends to member 12 and section 23 at pointsremote from hinge 24. A third form is shown in HQ. 7 wherein section 23is made of magnetic material, such as steel, and a permanent magnet 28is imbedded in member 13 during its manufacture on the opposite side ofplate 20' from section 23 so as to bias by magnetic force marking point23a into marking contact with the external surface of plate 20.

Vern-tracer unit 16 includes a markable surface element 29 and a tracerelement 39. Element 29 is a thin, flat steel plate attached to the uppermember 12, as high in the palate as possible, and adapted to receive thetracer marks forming the gothic arch placed thereon by tracer element 36in a manner to be described in more detail hereinafter. The surface ofplate 29 is oriented similar to the occlusal plane. Tracer element 39 iscarried by member 13 and is built as small and as compact as possiblebecause it goes into the oral cavity and must not interfere withcomfortable closing of the jaws. It includes a body portion 31 ofgenerally cylindrical form having a fiat transverse face 31a at one endand a reduced shank 31b at the other end with stepped cylindricalsurface 310 located therebetween. The body 31 is hollowed out to providean inner cavity or chamber 31d within which is mounted a tracer member32, the upper end of which protrudes through face 31a and is pointed at32a. The lower end of tracer member 32 lies within a reduced extension31c of chamber 31d.

Suitable operating means is provided for adjusting the tracer member 32longitudinally or endwise in chamber 31d in such manner as to vary theposition of its pointed end 32a. Tracer member 32 moves in a straightline along its axis, which is approximately normal to the occlusalplane, roughly indicated by the section line 33 of FIG. 1. Tracer member32 is a threaded screw, longitudinally slotted along one side to receivethe inner end of a headless set screw 34, which prevents rotation of thetracer member 32 but permits its endwise adjustment. On the screwthreads of tracer member 32 is mounted an internally threaded not oractuating member in the form of a bevel gear 35 meshing with a similarbevel gear 36 secured to the inner end of a shaft 37 rotatably mountedon a horizontal axis in a plug 38 secured into an opening in the tracerbody 31. Shaft 37 has a noncircular, such as a square or rectangular,recess 37a in its outer exposed end to receive the similarly shapedinner end of a key shaft 40 by means of which the gearing may be turnedin either direction.

Verti-tracer unit 16 includes a connecting means for detachablyconnecting tracer element 30 to lower member 13-. This includes aU-shaped support base 43, located in assembled position in FIG. 1between the horizontal U-shaped sections of members 12 and 13 in theocclusal plane, and a support bracket 45 secured thereto for supportingtracer element 30. Base 43 is formed of molded material and isdetachably connected to member 13 by a plurality of projections 46a,here shown as three in number, on base 43 projecting downwardlytherefrom and adapted to fit into corresponding detents 13a in thesurface of member 13. Bracket 45 has a. C-shaped portion 45a totelescopically and frictionally retain the cylindrical periphery 31c oftracer body 31 and has a plurality of spokes 4512, here shown as threein number, integrally secured thereto with the outer ends firmlyimbedded in the plastic material of base 43. A U-shaped cut-out 43b isformed in the upper surface of base 43 to receive the shaft 40 of theoperating key in the manner shown in FIG. 4. Hence, tracer element 30will be held in assembled position in the (Z-shaped portion 45a and base43 will be held in assembled position on member 13 by gravity so thatthe component parts will be prevented in this assembled position fromshifting in the horizontal or occlusal plane but may be readily liftedout or disassembled to remove one or all of them from member 13.

The markable surfaces of both plates 29 and 29 are now painted withtracing stains, and all parts so prepared are now sent to the dentistfor further adjustment in the mo uth of the patient.

First, the working bite is recorded. After moving tracer element 30 andbase 43- from member 13, the dentist places members 12 and 13 in themouth of the patient in proper association with the jaws. The patient isasked to bend forwardly from the hips, tilt his head forwardly and thenswallow. The working bite is then automatically recorded by the styluspoint 23w making a vertical mark 51 on the surface of plate 20' becausethe working bite is the closest approach attained between the jawsduring swallowing. It should be noted that there is no interference withthe normal swallowing action during this recording of the working bitebecause tracer element 30 and base 43 have been removed from the unit inFIG. 1 so that the patients tongue may move in its normal manner.

This graphical determination or recording of the Working bite by the actof swallowing may also be described more technically. The mandible(lower jaw) during the act of deglutition (swallowing) travels upwardlyfrom its vertical rest position to a centric position wherein itsarticulating co-ndyles are in centric relation with the glenoid fossaeand at this most superior position the agonistic and antagonistic musclefibers of suprahyoid and infrahyoid musculature acting on the mandiblecause it to be suspended in a position called the working bite. Anymoderately severe tactile interference acting on the mandible duringthis travel tends to stimulate proprioceptive neural reflex mechanismsassociated with the musculature to exert muscular forces causing themandible to assume a physiologically unnatural relationship. This tracergraphically records the uninhibited sagittal position of the mandible inits normal physiologic relationship so that registrations may then bemade in this desired position. As deglutition occurs, the mandible movesupwardly in uninhibited physiologic freedom and causes an inscription ofits distance of travel on the inked plate 20.

This working bite determines the particular vertical spacing betweenmembers 12 and 13 which provides or produces the desired, or the mostpleasing, appearance or external contour of the soft tissue, such as thelips.

Now, the dentist removes the members 12 and 13 from the patients mouth,and then draws a horizontal line 52 in FIG. 2 at the bottom of thevertical line 51 scribed by scriber point 23a during the swallowingprocess. Tracer element 30 and support base 43 are reassembled on member13, and then both members 12 and 13 are placed back on the articulator.Key shaft '40 is inserted into the socket 37a and turned until tracermember 32 has, by hearing against plate 29, separated members 12 and 13to the point wherein stylus point 231: is in horizontal alignment withhorizontal line 52. Members 12 and 13 are returned to the mouth and thevertical relationship between stylus point 23a and line 52 is checkedwith any needed adjustment being made by inserting and turning wrench40*. Now, the verti-scriber-tracer 21 may be removed from its sockettypesecuring sleeve 25.

The patient is now requested to move his jaws from side to side, asthough to grind his teeth, so as to record as a gothic arch 53 on themarkable surface of plate 29 the loci of the relative movement betweenthe jaws in the occlusal plane during grinding of the teeth whilemaintaining the working bite distance between the jaws. It should benoted that tracer element 30 has been heretofore firmly seated bygravity and friction in the bore of C-shaped portion 45a and that thethree projections 43a on the support base 43 have been similarly firmlyseated in the detents 13a of member 13. Now, they are more firmlypressed together by the pressure between tracer member 32 and plate 29.This construction and these forces prevent horizontal shift betweenthese components in the occlusal plane so that the gothic arch will beaccurately recorded. However, this tracer element 30 and base 43 areremovably mounted sothat they may be removed during the determination ofthe working bite and will not at that time cause any interference withthe natural swallowing action. This construction permits the dentist toobtain both the working bite and gothic arch with minimum work andalteration of the tracer components.

When tracing of the gothic arch is completed, the dentist removesmembers 12 and 13 from the mouth, and the tracing is further defined bydrawing bisecting lines on plate 29 at the apex of the arch 53. Then, aplastic disk, having a small hole therein, is placed over the markablesurface of plate 29 with this hole located 6 at the bisecting point ofthese lines, and the disk is sealed securely with wax to plate 29.

The dentist then returns members 12 and 13 to the mouth of the patient,and the patient is instructed to close his mouth until tracer memberpoint 32a comes in contact with this disk and then to slowly move thejaw right and left until the point 32a drops into the hole in the disk.Plaster is now injected completely around buccal and labial from left toright or vice versa. While the plaster is soft, the lips are allowed toform their own labial contour and also the normal lip line so that theplaster index actually takes an accurate impression of the patients lipson the tissue side. After the plaster has set, a center line is markedon its surface and the finished case is now ready to be removed from thepatients mouth and sent to the laboratory for setting of the teeth.

At the laboratory of the dental technician, members 12 and 13 aremounted on the models carried by the articulator. The lower member isnow remounted to a new centric and the articulator is locked intoposition with the plaster so that the vertical relationship cannot bechanged. Anterior teeth are set to conform with the angulation of theplaster on the bite block members 12 and 13. A tryin is sent to thedentist. After the dentist has processed the tryin cases, they arereturned to the articulator for final milling in by the dentaltechnician. Then, the finished cases are returned to the doctor for thepatient.

Various changes in details and arrangement of parts can be made by oneskilled in the art without departing from either the spirit of thisinvention or the scope of the appended claims.

What I claim is:

1. A method of determining the working bite position of the jaws of ahuman patient, comprising the steps of attaching a pair of members tothe jaws with one carried by the upper and the other by the lower jaw,inducing the patient to swallow with his head tilted forwardly, andrecording the closest approach between said jaws during swallowing bymarking on one of said members by means carried by the other of saidmembers.

2. A method of determining the working bite position and the gothic archof the jaws of a human patient, comprising the steps of attaching a pairof members to the jaws with one carried by the upper and the other bythe lower jaw, inducing the patient to swallow with his head tiltedforwardly, recording the closest approach between said jaws duringswallowing by marking on one of said members by means carried by theother of said members, and recording by one member on the other memberas a gothic arch the loci of the relative movement between the jaws inthe occlusal plane during grinding of the teeth while maintaining saidmarked and recorded closest approach between said jaws.

3. In an intra-oral tracer for determining the working bite, a pair ofmembers adapted to be carried respectively one by each jaw of a patient,and means operatively connecting said members for recording the workingbite distance between said jaws in response to swallowing by thepatient, said last mentioned means including a markable surface carriedby one of said members and including a tracer carried by the other ofsaid members, whereby said tracer will record on said surface theworking bite distance between said jaws when the patient swallows.

4. In an intra-oral tracer for determining the working bite, a pair ofmembers adapted to be carried respectively one by each jaw of a patient,and means operatively connecting said members for recording the workingbite distance between said jaws in response to swallowing by thepatient, said last mentioned means including a markable surface carriedby one of said members and extending generally normal to the occlusalplane and including a tracer carried by the other of said memberslooated'between said members and the lips of said patient and includingmeans biasing said tracer into marking contact against said surface,whereby said tracer will record on said surface the working bitedistance between said jaws when the patient swallows.

5. In an intra-oral tracer for determining the working bite and gothicarch, a pair of members adapted to be carried respectively one by eachjaw of a patient, means operatively connecting said members forrecording the working bite distance between said jaws in response toswallowing by the patient, said last mentioned means including amarkable surface carried by one of said members and including a tracerand including means detachably securing said tracer to the other of saidmembers so that said tracer can be removed from said other member whilethe patient grinds his teeth to record the gothic arch, and meansoperatively connecting said members for recording as a gothic arch theloci of the relative movement between the jaws in the occlusal planeduring grinding of the teeth while maintaining said working bitedistance between said jaws.

6. In an intra-oral tracer for determining the working bite, a pair ofmembers adapted to be carried respectively one by each jaw of a patient,and means operatively connecting said members for recording the workingbite distance between said jaws in response to swallowing by thepatient, said last mentioned means including a markable surface carriedby one of said members and extending generally normal to the: occlusalplane and including a tracer comprising two sections with one sectioncarried by the other of said members and including means biasing theother of said tracer sections into marking contact against said surface,said tracer including a hinge connecting said sections with the pivotaxis of said hinge extending generally parallel to said occlusal plane,whereby said tracer will record on said surface the working bitedistance between said jaws when the patient swallows.

7. The combination of claim 6 with said biasing means including a springoperatively connecting said sections together.

8. The combination of claim 6 with said bia'sing means including theother of said sections being made of ma netic material and including amagnet carried by the other of said members on the opposite side of saidsurface from said other section tobias said other section into markingcontact against said surface.

9. In an intra-oral tracer for determining the working bite and gothicarch, a pair of members adapted to be carried respectively one by eachjaw of a patient, means operatively connecting said members forrecording by a mark of one of said members the Working bite distancebetween said jaws in response to swallowing by the patient, and meansoperat-ively connecting said members for recording as a gothic arch theloci of the relative movement between the jaws in the occlusal planeduring grinding of the teeth while maintaining said working bitedistance between said jaws, said last mentioned means including a tracerelement carried by one of said members and including a markable surfaceelement oriented similarly to the occlusal plane and carried by theother of said members and including connecting means detachablyconnecting one of said elements to its associated member to permitremoval of said one element so that said one element does not interferewith the swallowing during recording of the working bite.

10. In an intra-oral tracer for determining the working bite and gothicarch, first and second members adapted to be carried respectively by thelower and upper jaws of a patient with the adjacent surfaces of saidmembers being generally U-shaped in the occlusal plane, meansoperatively connecting said members for recording the working bitedistance between said jaws in response to swallowing by the patient,said last mentioned means including a markable surface carried by saidfirst member and extending generally normal to the occlusal plane andincluding a tracer comprising two sections and including meansdetachably securing one of said tracer sections to said second memberwith the other of said tracer sections being located between saidmembers and the lips of said patient and bearing against said surfaceand including means biasing said other tracer section into markingcontact against said surface, said tracer including a hinge connectingsaid sections with the pivot axis of said hinge extending generallyparallel to said occlusal plane, said detachable securing meanspermitting said tracer to be removed from said second member while thepatient grinds his teeth to record the gothic arch, whereby said tracerwill record on said surface the working bite distance between said jawswhen the patient swallows, and means operatively connecting said membersfor recording as a gothic arch the loci of the relative movement betweenthe jaws in the occlusal plane during grinding of the teeth whilemaintaining said working bite distance between said jaws, said lastmentioned means including a tracer element carried by said first memberand including a markable surface element carried by said second memberand including connecting means detachably connecting said tracer elementto said first member in assembled position by gravity to prevent shifttherebetween in said occlusal plane so that said gothic arch will beaccurately recorded but to permit lifting out and removal of said tracerelement so that said tracer element does not interfere with-theswallowing during recording of the working bite, the portion of saidconnecting means carried by said tracer element being generally U-shapeand located in assembled position between the U-shapes of said members.

11. In an intra-oral tracer for determining the working bite, a pair ofmembers adapted to be carried respectively one by each jaw of a patient,and means on one of said members for establishing a mark on the other ofsaid members in a plane generally normal to the occlusal planeresponsive to relative movement of said members in response toswallowing by the patient to record the working bite distance betweensaid jaws.

References Cited in the file of this patent UNITED STATES PATENTS

